Growers aim to protect groundwater

Presentation of desal project highlights concern

Aug. 29, 2013

Written by

SOLEDAD — A Tuesday night presentation on one of the three key desalination projects moving forward on the Monterey Peninsula highlights what all the proposals’ proponents understand: They must pass muster with agriculture concerns in the Salinas Valley.

A couple of dozen growers and agri-business representatives listened to a presentation Tuesday night at Braga Ranch in Soledad advocating for the People’s Moss Landing Desalination Project, which, along with DeepWater Desal and California American Water Co.’s Monterey Peninsula Water Supply Project, is vying for the right to supply Peninsula residents and businesses with water once court-ordered cutbacks in pumping from the Carmel River go into effect in 2017.

What concerns growers is the potential for a final project to affect groundwater in the Salinas Valley Basin. Nader Agha, the managing partner and owner of the 200-acre Moss Landing Green Commercial Park LLC, which would be the site of the People’s Desal Project, told the assembled crowd that in addition to having much of the infrastructure already in place, the project is “not touching the Salinas Valley aquifer.”

Nancy Isakson, the president of the Salinas Valley Water Coalition, worries that the pumped, desalinated water could contain some fresh water. That would mean wells had tapped into a portion of an underground aquifer supplying growers in the valley with irrigation water. The act that created the Monterey County Water Resources Agency prohibits exporting Salinas Valley groundwater.

There are a number of reasons growers are protective of groundwater, aside from it being their only source if irrigation. One of the key reasons is the potential to exacerbate seawater intrusion that is already threatening the livelihoods of farmers in north Monterey County, and the areas west and immediately south of Salinas. While it depends on specific vegetables, crops generally cannot tolerate increases in salinity.

The Salinas Valley Water Project, which is operated by the county Water Resources Agency and paid for with assessments on agricultural property, has been making headway in slowing down the intrusion in recent years, mostly through groundwater recharging from the Salinas River.

(Page 2 of 2)

The worst hit of aquifers – they can be thought of as meandering underground lakes – is dubbed the “180” after the approximate depth and is a key water source for growers. Aquifers are layered atop one another and separated by solids that have nonporous characteristics of varying degrees, ranging from clay to sand. Below the 180 is a 400-foot aquifer that is also suffering from salt water intrusion, but at a slower rate.

“We are asking for 100 percent seawater [to be pumped],” Isakson said. “Any percentage of fresh water, then that’s considered ground water. We will not tolerate them drawing from the 180.”

In order for the dynamics of salt water intrusion to be reined in, aquifers must have adequate amounts of fresh water. Seawater intrusion became so bad in the Castroville area that the water agency developed the Castroville Seawater Intrusion Project to thwart its progress. That project diverts some water from the Salinas River at what’s known locally as the “rubber dam” in Marina (or the “diversion facility” if you are a water engineer) and mixes it with treated effluent before it is pumped to the Salinas and Castroville areas through the so-called “purple pipes.”

The thinking goes that growers are able to use water from CSIP’s purple pipes to irrigate crops and consequently are restricted from pumping from the 180 aquifer. Isakson explained the hydrology in that area of the basin produced a clay barrier separating a shallow aquifer from the 180-foot aquifer, making the 180 more difficult to recharge since clay allows percolation through it at a significantly slower rate.

“Growers in CSIP cannot pump from the 180; why allow CalAm?” she said.

There are areas even outside the CSIP area where no new wells drawing from the 180-foot aquifer can be dug, she added.

The problem is no one really knows whether or to what degree CalAm’s wells, or other projects, will draw from the basin. In late July a settlement agreement hammered out during a Public Utilities Commission proceeding established a technical team composed of a hydrologist and a hydrogeologist from the Salinas Valley Water Coalition and a hydrologist and other technical experts from CalAm. Data collected from the technical team study will shed light on whether, or to what extent, the desal wells (planned for the CEMEX site in Marina) will affect the Salinas Valley Groundwater Basin.

On Sept. 16 the PUC will hold a pre-hearing conference to consider outstanding issues from the settlement agreement. One of the issues is the timing of a draft environmental study on the project the PUC plans to release in February. But Isakson said the data from the technical team will not be available by February and questioned the validity of any environmental study that does not include that data.

Meanwhile, Norm Groot, executive director of the Monterey County Farm Bureau, said Tuesday after the People’s Desal presentation that his organization has not endorsed any specific project, a view echoed by Isakson.

“It’s an option to be looked at,” she said.

Dennis L. Taylor writes about agriculture and water issues for The Californian. Follow him on Twitter @taylor_salnews.